Channel state information reporting for random access procedures

ABSTRACT

Methods, systems, and devices for wireless communication are described. A user equipment (UE) may receive, from a base station, a downlink transmission in a radio frequency spectrum band and may identify reference resources in the downlink transmission for computing a channel state information (CSI) report. The UE may generate the CSI report based at least in part on the identified reference resources and transmit, in the radio frequency spectrum band, the CSI report in a random access request message to the base station. The base station may receive the request message and identify CSI associated with the band based at least in part on the CSI report included in the random access request message. The base station may transmit, to the UE, a random access response message based at least in part on the identified CSI in the radio frequency spectrum band.

CROSS REFERENCES

The present Application for Patent claims priority to U.S. ProvisionalPatent Application No. 62/346,056 by Yerramalli et al., entitled“Channel State information Reporting For Random Access Procedures,”filed Jun. 6, 2016, assigned to the assignee hereof, and which is herebyexpressly incorporated by reference herein in its entirety.

BACKGROUND

The following relates generally to wireless communication, and morespecifically to channel state information (CSI) reporting for randomaccess procedures.

Wireless communications systems are widely deployed to provide varioustypes of communication content such as voice, video, packet data,messaging, broadcast, and so on. These systems may be capable ofsupporting communication with multiple users by sharing the availablesystem resources (e.g., time, frequency, and power). Examples of suchmultiple-access systems include code division multiple access (CDMA)systems, time division multiple access (TDMA) systems, frequencydivision multiple access (FDMA) systems, and orthogonal frequencydivision multiple access (OFDMA) systems, (e.g., a Long Term Evolution(LTE) system, a New Radio (NR) system). A wireless multiple-accesscommunications system may include a number of base stations, eachsimultaneously supporting communication for multiple communicationdevices, which may be referred to as user equipment (UE).

SUMMARY

A user equipment (UE) may use a shortened random access procedure toestablish a communication connection with a base station operating in aradio frequency spectrum band, including in an unlicensed radiofrequency spectrum band. The UE may provide channel state information(CSI) in a CSI report in a random access request message to the basestation during the first step of the shortened random access procedure.The CSI may include at least a channel quality information (CQI), aprecoding matrix indicator (PMI), a rank indicator (RI), or acombination of these. The UE may determine the reference resources to beused to determine the CSI based at least in part on apreviously-received downlink transmission, which may include a downlinkreference signal. The downlink transmission can be a connectionpre-establishment message sent by the base station, and may have includeinformation blocks such as a system information block (SIB), thatprovide an indication identifying the resources that the UE is to use togenerate the CSI for the CSI report. After receiving the random accessrequest message from the UE, the base station may then schedule, basedat least in part on the CSI in the CSI report received from the UE, arandom access response message during the second step of the shortenedrandom access procedure.

A method of wireless communication is described. The method may includereceiving, from a base station, a downlink transmission in a radiofrequency spectrum band, identifying reference resources in the downlinktransmission for computing a CSI report, generating the CSI report basedat least in part on the identified reference resources, andtransmitting, in the radio frequency spectrum band, the CSI report in arandom access request message to the base station.

An apparatus for wireless communication is described. The apparatus mayinclude means for receiving, from a base station, a downlinktransmission in a radio frequency spectrum band, means for identifyingreference resources in the downlink transmission for computing a CSIreport, means for generating the CSI report based at least in part onthe identified reference resources, and means for transmitting, in theradio frequency spectrum band, the CSI report in a random access requestmessage to the base station.

Another apparatus for wireless communication is described. The apparatusmay include a processor, memory in electronic communication with theprocessor, and instructions stored in the memory. The instructions maybe operable to cause the processor to receive, from a base station, adownlink transmission in a radio frequency spectrum band, identifyreference resources in the downlink transmission for computing a CSIreport, generate the CSI report based at least in part on the identifiedreference resources, and transmit, in the radio frequency spectrum band,the CSI report in a random access request message to the base station.

A non-transitory computer readable medium for wireless communication isdescribed. The non-transitory computer-readable medium may includeinstructions operable to cause a processor to receive, from a basestation, a downlink transmission in a radio frequency spectrum band,identify reference resources in the downlink transmission for computinga CSI report, generate the CSI report based at least in part on theidentified reference resources, and transmit, in the radio frequencyspectrum band, the CSI report in a random access request message to thebase station.

Some examples of the method, apparatus, or non-transitorycomputer-readable medium described above may further include processes,features, means, or instructions for receiving, from the base station, arandom access response message generated by the base station based atleast in part on CSI in the CSI report.

Some examples of the method, apparatus, or non-transitorycomputer-readable medium described above may further include processes,features, means, or instructions for receiving a connectionpre-establishment message from the base station, wherein identifying thereference resources comprises decoding an information block included inthe connection pre-establishment message, wherein the information blockcomprises an indication that identifies the reference resources to beused to generate the CSI report.

In some examples of the method, apparatus, or non-transitorycomputer-readable medium described above, receiving the downlinktransmission comprises detecting a subframe transmitted by the basestation.

In some examples of the method, apparatus, or non-transitorycomputer-readable medium described above, the CSI report comprises achannel quality indicator, or a precoding matrix indicator, or a rankindicator, or a combination thereof.

In some examples of the method, apparatus, or non-transitorycomputer-readable medium described above, the reference resourcescomprise a dedicated reference signal used for downlink synchronizationwith the base station.

In some examples of the method, apparatus, or non-transitorycomputer-readable medium described above, generating the CSI reportfurther comprises processing the reference resources to obtain areference signal. Some examples of the method, apparatus, ornon-transitory computer-readable medium described above may furtherinclude processes, features, means, or instructions for calculating CSIto be included in the CSI report based at least in part on the referencesignal.

In some examples of the method, apparatus, or non-transitorycomputer-readable medium described above, the reference signal is one ormore of a dedicated reference signal, a cell-specific reference signal,or a CSI reference signal.

Some examples of the method, apparatus, or non-transitorycomputer-readable medium described above may further include processes,features, means, or instructions for indicating in the random accessrequest message which one or more of a plurality of reference resourceswas used to generate the CSI report.

Some examples of the method, apparatus, or non-transitorycomputer-readable medium described above may further include processes,features, means, or instructions for determining that a random accessresponse message has not yet been received in response to the randomaccess request message. Some examples of the method, apparatus, ornon-transitory computer-readable medium described above may furtherinclude processes, features, means, or instructions for retransmittingthe random access request message to the base station in the radiofrequency spectrum band.

Some examples of the method, apparatus, or non-transitorycomputer-readable medium described above may further include processes,features, means, or instructions for calculating an updated CSI report,wherein the retransmitted random access request message comprises theupdated CSI report.

In some examples of the method, apparatus, or non-transitorycomputer-readable medium described above, the radio frequency spectrumband may include a shared radio frequency spectrum band.

A method of wireless communication is described. The method may includereceiving, from a UE, a random access request message in a radiofrequency spectrum band, the random access request message including aCSI report, identifying CSI associated with the radio frequency spectrumband based at least in part on the CSI report included in the randomaccess request message, and transmitting, to the UE, a random accessresponse message based at least in part on the identified CSI in theradio frequency spectrum band.

An apparatus for wireless communication is described. The apparatus mayinclude means for receiving, from a UE, a random access request messagein a radio frequency spectrum band, the random access request messageincluding a CSI report, means for identifying CSI associated with theradio frequency spectrum band based at least in part on the CSI reportincluded in the random access request message, and means fortransmitting, to the UE, a random access response message based at leastin part on the identified CSI in the radio frequency spectrum band.

Another apparatus for wireless communication is described. The apparatusmay include a processor, memory in electronic communication with theprocessor, and instructions stored in the memory. The instructions maybe operable to cause the processor to receive, from a UE, a randomaccess request message in a radio frequency spectrum band, the randomaccess request message including a CSI report, identify CSI associatedwith the radio frequency spectrum band based at least in part on the CSIreport included in the random access request message, and transmit, tothe UE, a random access response message based at least in part on theidentified CSI in the radio frequency spectrum band.

A non-transitory computer readable medium for wireless communication isdescribed. The non-transitory computer-readable medium may includeinstructions operable to cause a processor to receive, from a UE, arandom access request message in a radio frequency spectrum band, therandom access request message including a CSI report, identify CSIassociated with the radio frequency spectrum band based at least in parton the CSI report included in the random access request message, andtransmit, to the UE, a random access response message based at least inpart on the identified CSI in the radio frequency spectrum band.

Some examples of the method, apparatus, or non-transitorycomputer-readable medium described above may further include processes,features, means, or instructions for communicating with the UE in theradio frequency spectrum band based at least in part on the identifiedCSI.

Some examples of the method, apparatus, or non-transitorycomputer-readable medium described above may further include processes,features, means, or instructions for transmitting a downlinktransmission in the radio frequency spectrum band, the downlinktransmission comprising reference resources to enable the UE to generatethe CSI report.

In some examples of the method, apparatus, or non-transitorycomputer-readable medium described above, transmitting the downlinktransmission comprises matching a rate of a physical uplink controlchannel to a rate of the reference resources.

In some examples of the method, apparatus, or non-transitorycomputer-readable medium described above, transmitting of the downlinktransmission comprises generating the downlink transmission to includean information block indicating that CSI reporting is enabled.

In some examples of the method, apparatus, or non-transitorycomputer-readable medium described above, the information blockindicates wideband reporting, sub-band reporting, or UE-selectedsub-band reporting.

Some examples of the method, apparatus, or non-transitorycomputer-readable medium described above may further include processes,features, means, or instructions for processing the random accessrequest message to identify a CSI report indicator indicating that therandom access request message includes the CSI report.

In some examples of the method, apparatus, or non-transitorycomputer-readable medium described above, the radio frequency spectrumband may include a shared radio frequency spectrum band.

The foregoing has outlined rather broadly the features and technicaladvantages of examples according to the disclosure in order that thedetailed description that follows may be better understood. Additionalfeatures and advantages will be described hereinafter. The conceptionand specific examples disclosed may be readily utilized as a basis formodifying or designing other structures for carrying out the samepurposes of the present disclosure. Such equivalent constructions do notdepart from the scope of the appended claims. Characteristics of theconcepts disclosed herein, both their organization and method ofoperation, together with associated advantages will be better understoodfrom the following description when considered in connection with theaccompanying figures. Each of the figures is provided for the purpose ofillustration and description only, and not as a definition of the limitsof the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an example of a wireless communications system inaccordance with aspects of the present disclosure;

FIG. 2 illustrates an example of a flow diagram that supports channelstation information (C SI) reporting for random access procedures inaccordance with aspects of the present disclosure;

FIG. 3 illustrates an example of a flow diagram that supports CSIreporting for random access procedures in accordance with aspects of thepresent disclosure;

FIGS. 4 through 6 show block diagrams of wireless devices that supportCSI reporting for random access procedures in accordance with aspects ofthe present disclosure;

FIG. 7 illustrates a block diagram of a system including a wirelessdevice that supports CSI reporting for random access procedures inaccordance with aspects of the present disclosure;

FIGS. 8 through 10 show block diagrams of wireless devices that supportCSI reporting for random access procedures in accordance with aspects ofthe present disclosure;

FIG. 11 illustrates a block diagram of a system including a wirelessdevice that supports CSI reporting for random access procedures inaccordance with aspects of the present disclosure;

FIGS. 12 through 16 show flowcharts illustrating methods that supportCSI reporting for random access procedures in accordance with aspects ofthe present disclosure.

DETAILED DESCRIPTION

In some wireless communications systems (e.g., a Long Term Evolution(LTE) network), UEs may share limited network resources. When firstattempting to access a conventional LTE network, a user equipment (UE)may perform an initial handshake and synchronization process with a basestation. Once synchronized, the UE may read one or more systeminformation blocks (SIBs) that contain parameters that may be used forinitial access to the network. A UE may desire to send an uplinktransmission to a base station, and may accordingly initiate a randomaccess procedure (e.g., a random access channel (RACH) process) torequest access to the network and use network resources.

In certain LTE systems, the UE and base station perform a 4 messageprocedure of exchanging messages msg1 to msg4. In msg1 the UE mayrandomly select one of 64 preambles and send the selected preamble tothe base station. In msg2 the base station may send a response messageto the UE on a downlink shared channel (DL-SCH). The random accessresponse message may include a temporary cell radio network temporaryidentifier (C-RNTI) assigned to the UE, a timing advance value, and anuplink grant resource so that the UE can use an uplink shared channel(UL-SCH). In msg3 the UE may use the UL-SCH to send a radio resourcecontrol (RRC) connection request message to the base station. In msg4the base station may respond to the UE with a connection resolutionmessage, including among other things a new C-RNTI that the UE may usefor further communications with the base station. However, messages sentby the base station as part of the random access procedure may not takeinto account channel conditions associated with the UE, and the basestation may thus be unable to efficiently and quickly schedulecommunications with the UE during the acquisition procedure.

A 2-step random access procedure, or RACH procedure, may include a step1 that is effectively a combination of msg1 and msg3 sent from the UE tothe base station as described above, and a step 2 that is effectively acombination of msg2 and msg4 sent from the base station to the UE, alsoas described above. Prior to or as part of step 1 of this shortenedrandom access procedure, the UE may decode an evolved SIB (eSIB) orother information block received from the base station to obtain theparameters that the UE needs to send a RACH transmission. If in an RRCconnected mode, the UE may include a medium access control (MAC) C-RNTI,buffer status report (BSR), or the like, in a message sent to the basestation in step 1. If not in an RRC connected mode, then the UE may senda common control channel (CCCH) service data unit (SDU) to the basestation in step 1.

The examples disclosed herein improve on random access procedures forUEs. In some cases, the described random access procedures may beperformed by UEs operating in a shared radio frequency spectrum band,including in an unlicensed radio frequency spectrum band. Additionallyor alternatively, the described random access procedures may beperformed by UEs operating in a licensed radio frequency spectrum band.Channel state information (CSI) may be included in the step 1 of a2-step random access procedure (e.g., as part of the contents of msg1).In an example, a UE may process reference resources received in downlinktransmissions from a base station to generate a CSI report, and send theCSI report in a shared radio frequency band to the base station in arandom access request message. The base station may more quicklyallocate resources to the UE for uplink transmission with the basestation via the shared radio frequency band as compared with theabove-discussed 4 message technique. For example, the base station canuse the provided CSI information in the CSI report to more efficientlyschedule the step 2 message for the UE (e.g., as part of the msg2contents).

The UE may establish communications with a base station when operatingin a shared radio frequency spectrum band, including in an unlicensedradio frequency spectrum band. The UE may use a shortened random accessprocedure to establish a communication connection during an acquisitionprocedure. In some examples, the shortened random access procedure mayhave two steps rather than four as in certain legacy LTEimplementations. The UE may provide CSI (e.g., a channel qualityinformation (CQI), a precoding matrix indicator (PMI), a rank indicators(RI), or a combination) in a CSI report in a random access requestmessage to the base station during step 1 of the shortened random accessprocedure. The UE may determine the reference resources to be used todetermine the CSI based on a previously-received downlink transmission,which may include a downlink reference signal. The downlink transmissioncan be a connection pre-establishment message sent by the base station,for example including an eSIB as described above, that provide anindication identifying the resources that the UE is to use to generatethe CSI for the CSI report. After receiving the random access requestmessage from the UE, the base station may then schedule a random accessresponse message during step 2 based on the CSI in the CSI report,improving the speed and efficiency of communications between the basestation and the UE.

Aspects of the disclosure are initially described in the context of awireless communications system. A UE of the wireless communicationssystem may expedite allocation of resources for uplink communication toa base station in a shared radio frequency spectrum band by transmittinga CSI report to the base station during a random access procedure.Aspects of the disclosure are further illustrated by and described withreference to apparatus diagrams, system diagrams, and flowcharts thatrelate to CSI reporting for random access procedures.

In some instances, a shared radio frequency spectrum band may referspecifically to spectrum that is lightly licensed and/or in which theremay be some level of coordination among communications of differentradio access technologies (RATs) or some level of preference given tocommunications of a particular RAT, such as an incumbent RAT, forexample. In other instances, a shared radio frequency spectrum band mayrefer generally to spectrum in which different RATs coexist or operatewithin the same RF spectrum band, which may include lightlylicensed/coordinated spectrum or, alternatively, purely unlicensedspectrum in which different RATs may freely contend for access to thechannel medium using various channel contention techniques. The aspectsdescribed in the present disclosure may be applicable to various sharedor unlicensed spectrum regimes. Accordingly, the terms shared spectrumand unlicensed spectrum are used interchangeably herein unless otherwisenoted.

FIG. 1 illustrates an example of a wireless communications system 100 inaccordance with various aspects of the present disclosure. The wirelesscommunications system 100 includes base stations 105, UEs 115, and acore network 130. In some examples, the wireless communications system100 may be a LTE network, a LTE-Advanced (LTE-A) network, a New Radio(NR) network, or the like. The wireless communications system 100 mayenable each UE 115 to process reference resources in one or moredownlink transmissions. Additionally or alternatively, wirelesscommunications system 100 may include a wireless local area network(WLAN) (also known as a Wi-Fi network) or a MuLTEFire network. A UE 115may include a UE CSI Reporting Manager 415 to generate and communicate arandom access request message that includes a CSI report via a sharedradio frequency transmission medium. Additional aspects of the UE CSIReporting Manager 415 as described below with reference to FIG. 4. Abase station 105 may include a base station CSI Reporting Manager 815 toprocess the random access request message and to send a random accessresponse message. Additional aspects of the base station CSI ReportingManager 815 as described below with reference to FIG. 8. Because a basestation 105 receives the CSI report in the random access requestmessages, the base station 105 may more quickly allocate networkresources to the UE 115 with less signaling as compared to conventionaltechniques.

Base stations 105 may wirelessly communicate with UEs 115 via one ormore base station antennas. Each base station 105 may providecommunication coverage for a respective geographic coverage area of acell 110. Communication links 125 shown in wireless communicationssystem 100 may include uplink transmissions from a UE 115 to a basestation 105, or downlink transmissions, from a base station 105 to a UE115.

UEs 115 may be dispersed throughout the wireless communications system100, and each UE 115 may be stationary or mobile. A UE 115 may also bereferred to as a mobile station, a subscriber station, a mobile unit, asubscriber unit, a wireless unit, a remote unit, a mobile device, awireless device, a wireless communications device, a remote device, amobile subscriber station, an access terminal (AT), a mobile terminal, awireless terminal, a remote terminal, a handset, a user agent, a mobileclient, a client, or some other suitable terminology. A UE 115 may alsobe a cellular phone, a personal digital assistant (PDA), a wirelessmodem, a wireless communication device, a handheld device, a tabletcomputer, a laptop computer, a cordless phone, a personal electronicdevice, a handheld device, a personal computer, a wireless local loop(WLL) station, an Internet of Things (IoT) device, a narrowband IoT(NB-IoT) device, an Internet of Everything (IoE) device, a machine-typecommunication (MTC) device, an appliance, an automobile, or the like.

A MuLTEFire network may include APs and/or base stations 105communicating in an unlicensed radio frequency spectrum band without alicensed frequency anchor carrier. For example, the MuLTEFire networkmay operate without an anchor carrier in the licensed spectrum. Wirelesscommunications system 100 may support reference signal transmissions anddecoding techniques that may increase the efficiency of MuLTEFirecommunications within wireless communications system 100. Aspects ofwireless communications system 100 configured as a MuLTEFire networkwith MuLTEFire eNB as base stations 105 and may include WLAN accesspoints (APs). For example, wireless communications system 100 mayinclude aspects of an LTE/LTE-A network, a Wi-Fi network, a MuLTEFirenetwork, a neutral host small cell network, or the like, operating withoverlapping coverage areas.

Enhanced MTC (eMTC) and NB-IoT protocols may be associated with lowpower wide area radio technologies that enable a MTC device, an IoTdevice, or both to connect using cellular telecommunications bands. MTCdevices may typically include a battery, and are designed to consume lowamounts of power while handling fairly infrequent two-way datacommunication. NB-IoT technology may be deployed “in-band” such thatthat spectrum allocated to a cellular network (e.g., an LTE network) maybe used for communication, or in a standalone deployment in which IoTdevices communicate using spectrum separate from other deployments forIoT communication. In some examples, NB-IoT may use a bandwidth of 180KHz, where eMTC technology may use a bandwidth of 1.08 MHz, which may bea subset of the bandwidth for a carrier (e.g., an LTE carrier, which mayhave a bandwidth of up to 20 MHz). eMTC and NB-IoT may have otherrestrictions on coding, modulation, data rate, or the like.

In some cases, a UE 115 may also be able to communicate directly withother UEs (e.g., using a peer-to-peer (P2P) or device-to-device (D2D)protocol). One or more of a group of UEs 115 utilizing D2Dcommunications may be within the coverage area of a cell 110. Other UEs115 in such a group may be outside the coverage area of a cell 110, orotherwise unable to receive transmissions from a base station 105. Insome cases, groups of UEs 115 communicating via D2D communications mayutilize a one-to-many (1:M) system in which each UE 115 transmits toevery other UE 115 in the group. In some cases, a base station 105facilitates the scheduling of resources for D2D communications. In othercases, D2D communications are carried out independent of a base station105.

Some UEs 115, such as MTC or IoT devices, may be low cost or lowcomplexity devices, and may provide for automated communication betweenmachines, i.e., Machine-to-Machine (M2M) communication. M2M or MTC mayrefer to data communication technologies that allow devices tocommunicate with one another or a base station without humanintervention. For example, M2M or MTC may refer to communications fromdevices that integrate sensors or meters to measure or captureinformation and relay that information to a central server orapplication program that can make use of the information or present theinformation to humans interacting with the program or application. SomeUEs 115 may be designed to collect information or enable automatedbehavior of machines. Examples of applications for MTC devices includesmart metering, inventory monitoring, water level monitoring, equipmentmonitoring, healthcare monitoring, wildlife monitoring, weather andgeological event monitoring, fleet management and tracking, remotesecurity sensing, physical access control, and transaction-basedbusiness charging.

Base stations 105 may communicate with the core network 130 and with oneanother. For example, base stations 105 may interface with the corenetwork 130 through backhaul links 132 (e.g., S1, etc.). Base stations105 may communicate with one another over backhaul links 134 (e.g., X2,etc.) either directly or indirectly (e.g., through core network 130).Base stations 105 may perform radio configuration and scheduling forcommunication with UEs 115, or may operate under the control of a basestation controller (not shown). In some examples, base stations 105 maybe macro cells, small cells, hot spots, or the like. Base stations 105may also be referred to as eNodeBs (eNBs) 105. Base stations 105 mayalso be MuLTEFire base stations 105, which may have limited or non-idealbackhaul links 134 with other base stations 105. In some cases, basestation 105 may refer to an AP of a WLAN.

Wireless communications systems are widely deployed to provide varioustypes of communication content such as voice, video, packet data,messaging, broadcast, and so on. These systems may be capable ofsupporting communication with multiple users by sharing the availablesystem resources (e.g., time, frequency, and power). Examples of suchmultiple-access systems include code division multiple access (CDMA)systems, time division multiple access (TDMA) systems, frequencydivision multiple access (FDMA) systems, and orthogonal frequencydivision multiple access (OFDMA) systems. A wireless multiple-accesscommunications system may include a number of base stations, eachsimultaneously supporting communication for one or more multiplecommunication devices, which may be otherwise known as a UE. In somecases, a wireless communications system may include narrowband internetof things (NB-IoT) devices. In some cases, wireless communicationssystem 100 may utilize enhanced component carriers (eCCs). An eCC may becharacterized by one or more features including: wider bandwidth,shorter symbol duration, shorter transmission time interval (TTIs), andmodified control channel configuration. In some cases, an eCC may beassociated with a carrier aggregation configuration or a dualconnectivity configuration (e.g., when multiple serving cells have asuboptimal or non-ideal backhaul link). An eCC may also be configuredfor use in unlicensed spectrum or shared spectrum (where more than oneoperator is allowed to use the spectrum). An eCC characterized by widebandwidth may include one or more segments that may be utilized by UEs115 that are not capable of monitoring the whole bandwidth or prefer touse a limited bandwidth (e.g., to conserve power).

In some cases, an eCC may utilize a different symbol duration than otherCCs, which may include use of a reduced symbol duration as compared withsymbol durations of the other CCs. A shorter symbol duration isassociated with increased subcarrier spacing. A device, such as a UE 115or base station 105, utilizing eCCs may transmit wideband signals (e.g.,20, 40, 60, 80 MHz, etc.) at reduced symbol durations (e.g., 16.67microseconds). A TTI in eCC may consist of one or multiple symbols. Insome cases, the TTI duration (that is, the number of symbols in a TTI)may be variable. In some cases, an eCC may utilize a different symbolduration than other CCs, which may include use of a reduced symbolduration as compared with symbol durations of the other CCs. A shortersymbol duration is associated with increased subcarrier spacing. Adevice, such as a UE 115 or base station 105, utilizing eCCs maytransmit wideband signals (e.g., 20, 40, 60, 80 MHz, etc.) at reducedsymbol durations (e.g., 16.67 microseconds). A TTI in eCC may consist ofone or multiple symbols. In some cases, the TTI duration (that is, thenumber of symbols in a TTI) may be variable.

A shared radio frequency spectrum band may be utilized in an NR sharedspectrum system. For example, an NR shared spectrum may utilize anycombination of licensed, shared, and unlicensed spectrums, among others.The flexibility of eCC symbol duration and subcarrier spacing may allowfor the use of eCC across multiple spectrums. In some examples, NRshared spectrum may increase spectrum utilization and spectralefficiency, specifically through dynamic vertical (e.g., acrossfrequency) and horizontal (e.g., across time) sharing of resources.

The wireless communications system 100 may expeditiously allocateresources to UE 115 for uplink transmission to the base station 105 ascompared to conventional techniques. In an example, the UE 115 mayreceive, from the base station 105, a downlink transmission in a sharedradio frequency spectrum band. The UE 115 may identify referenceresources in the downlink transmission for computing a CSI report. TheUE 115 may generate the CSI report based on the identified referenceresources and transmit, in the shared radio frequency spectrum band, theCSI report in a random access request message to the base station 105.Upon receipt, the base station 105 may identify CSI associated with theshared radio frequency spectrum band based on the CSI report included inthe random access request message. The base station 105 may transmit, tothe UE 115, a random access response message based on the identified CSIin the shared radio frequency spectrum band.

FIG. 2 illustrates an example of a flow diagram 200 that supports CSIreporting for random access procedures in accordance with aspects of thepresent disclosure. In some cases, flow diagram 200 may representaspects of techniques performed by a UE 115 or base station 105 asdescribed with reference to FIG. 1. UE 115-a is an example of UE 115 andbase station 105-a is an example of base station 105 as described withreference to FIG. 1.

At 202, the base station 105-a may transmit one or more downlinktransmissions in a radio frequency spectrum band. The downlinktransmission may be sent as one or more frames including one or moresubframes on a downlink channel. The radio frequency spectrum band maybe, for example, a radio frequency band in the unlicensed spectrum.Additionally or alternatively, the base station 105-b may transmit thedownlink transmissions in a radio frequency band in the licensedspectrum.

In an example, the base station 105-a may broadcast one or more downlinktransmissions on a downlink channel to any UE 115 within its coveragearea. For example, the downlink transmission may be a connectionpre-establishment message that includes one or more of a primarysynchronization signal (PSS), a secondary synchronization signal (SSS),a master information block (MIB), an eSIB, or the like. Each downlinktransmission may include one or more reference resources that the UE115-a may use to calculate CSI. Examples of reference resources mayinclude a dedicated reference signal (DRS), a cell-specific referencesignal (CRS), a CSI reference signal (CSI-RS), CSI interferencemeasurement (CSI-IM) resources, or any combination thereof, or the like.The UE 115-a may use the DRS for downlink synchronization with the basestation 105-a. The CSI-RS may be transported in a regular subframe or aspart of DRS configuration. The UE 115-a may use some or all of thereference resources to calculate CSI. The UE 115-a or the base station105-a may indicate which resources to use. In an example, the UE 115-amay decode the connection pre-establishment message (e.g., to decode theMIB, eSIB, etc.) and identify an indication of which reference resourcesto use to generate the CSI for the CSI report.

The base station 105-a may also have knowledge of rate matching to beused for a physical uplink shared channel (PUSCH), physical uplinkcontrol channel (PUCCH), or both, and may match the rate of thereference resources transmitted in the downlink transmission to thePUSCH rate, the PUCCH rate, or both. The downlink transmission may alsouse one or more information blocks (e.g., eSIB, MIB, etc.) to indicatewhether CSI reporting is enabled (e.g., information block includes anindicator to indicate whether CSI reporting is enabled) and the type ofreporting enabled. Types of reporting may include wideband, sub-band, orUE-selected sub-band reporting.

At 204, the UE 115-a may receive the downlink transmission, identifyreference resources in the downlink transmission, and generate a CSIreport based on the identified resources. To generate the CSI report,the UE 115-a may calculate CSI based on the reference resources.

Examples of CSI include a CQI, a PMI, and a rank indicator (RI), whichmay include sub-band reporting. The CQI may be data indicating how goodor bad a communication channel is. In an example, the CQI may indicate asuitable data transmission rate (e.g., a modulation and coding scheme(MCS) value) for downlink transmissions to the UE 115-a. The CQI may bebased on a measurement of a received downlinksignal-to-interference-plus-noise ratio (SINR) and characteristics of areceiver of UE 115-a. The PMI may identify which precoding matrix to usefor downlink transmissions to the UE 115-a. For example, the PMI mayspecify a codebook index to be used by the base station 105-a whentransmitting to the UE 115-a. The RI may indicate a number transmissionlayers used for spatial multiplexing (e.g., based on the UE's estimateof a downlink channel) when transmitting to the UE 115-a. For example,the base station 105-a may adapt physical downlink shared channel(PDSCH) transmissions to the UE 115-a based on the RI.

At 206, the UE 115-a may generate and transmit, to the base station105-a, a random access request message including the CSI report. Togenerate the random access request message, the UE 115-a may select arandom access preamble of multiple preambles (e.g., 64 availablepreambles), and include the selected preamble and CSI report in therandom access request message. In an example, the UE 115-a may transmitthe random access request message on a RACH of the shared radiofrequency spectrum band. In another example, the UE 115-a may transmitthe random access request message on a RACH of the licensed radiofrequency spectrum band. The random access request message may alsoindicate which reference resources were used to generate the CSIincluded in the CSI report. For example, the random access requestmessage may indicate that one or more of the DRS, CRS, and CSI-RS wereused. In some examples, the random access request message may include aCSI indicator indicating whether the random access request messageincludes a CSI report.

At 208, the base station 105-a may identify the CSI included in a CSIreport of the random access request message based on the received randomaccess request message. In an example, the base station 105-a may assumethat, since the downlink transmission includes reference resources forcomputing CSI, that the random access request message may include a CSIreport. In another example, the UE 115-a may include a CSI indictor in apayload of the random access request message to indicate whether CSI isbeing reported.

The base station 105-a may use the CSI from the CSI report forcommunicating with and allocating resources to the UE 115-a for uplinktransmission. For example, the base station 105-a may select one or moreof an MCS, a precoding matrix, or a number of layers to use forcommunication with the UE 115-a based on CQI or the MCS value, precodingmatrix, or RI, respectively, specified by the CSI report.

The base station 105-a may also derive information for allocatingresources for uplink transmission based on when the random accessrequest message is received. For example, the base station 105-a mayestimate uplink transmission timing of the UE 115-a and derive a randomaccess radio network temporary identifier (RA-RNTI) from a timeslotnumber on the RACH in which the random access request message isreceived. The base station 105-a may also assign a temporary C-RNTI tothe UE 115-a and use the temporary C-RNTI to address the UE 115-a insubsequent messages.

At 210, the base station 105-a may transmit a random access responsemessage to the UE 115-a via a downlink shared channel (DL-SCH) based oninformation included in the CSI report. For example, the base station105-a may transmit the random access response message in accordance withCQI or the MCS value, precoding matrix, or RI, or any combinationthereof, specified by the CSI report. The random access response messagemay also include timing and uplink resource allocated to the RA-RNTI, atiming advance value, a MAC random access response (RAR), or the like.The random access response message may also include a back off indicatorMAC header for controlling a backoff duration in the event of a randomaccess procedure failure.

In some examples, the UE 115-a may not receive the random accessresponse message within a predetermined amount of time. The UE 115-a maythen retransmit the random access request message one or more times. Inone example, the retransmitted random access request message may includea copy of the previously sent CSI report. In another example, the UE115-a may calculate an updated CSI report based on current conditions ofa communication channel and retransmit the random access request messagewith the updated CSI report.

In exchanging two messages (e.g., the random access request and responsemessages), the UE 115-a and base station 105-a may have exchanged theinformation for allocating resources to the UE 115-a for uplinktransmission to the base station 105-a via a random access procedure.Beneficially, the UE 115-a may more quickly begin sending uplinktransmissions as compared to conventional solutions.

At 212, and following establishment of the connection, the base station105-a and UE 115-a may communicate via the radio frequency band (e.g.,in the shared radio frequency band, in the licensed radio frequencyband) in accordance with the CSI from the CSI report.

FIG. 3 illustrates an example of a flow diagram 300 that supports CSIreporting for random access procedures in accordance with aspects of thepresent disclosure. In some cases, flow diagram 300 may representaspects of techniques performed by a UE 115 or base station 105 asdescribed with reference to FIG. 1. UE 115-b is an example of UE 115 andbase station 105-b is an example of base station 105 described withreference to FIG. 1.

In some examples, the UE 115-b may not immediately initiate a randomaccess procedure in response to receiving a downlink transmission fromthe base station 105-b. In the example flow diagram 300 of FIG. 3, thebase station 105-b may send two or more downlink transmissions 202before UE 115-b decides to send a random access request message. Asdepicted, the base station 105-b sends two downlink transmissions, 202-aand 202-b, at which the UE 115-b initiates a random access procedurefollowing the second downlink transmission 202-b. That is, a UE 115 maydetermine to initiate the described random access procedure followingany downlink transmission, and the described random access proceduredoes not necessarily follow each downlink transmission received from abase station 105.

The remaining aspects of FIG. 3 may be the same as the aspects asdescribed with reference to FIG. 2. For example, at 204-a, the UE 115-bmay receive the downlink transmission, identify reference resources inthe downlink transmission, and generate a CSI report based on theidentified resources. At 206-a, the UE 115-b may generate and transmit,to the base station 105-b, a random access request message including theCSI report. At 208-a, the base station 105-b may receive the randomaccess request message and identify the CSI included in a CSI report ofthe random access request message. At 210-b, the base station 105-a maytransmit a random access response message to the UE 115-b via a DL-SCHbased on information included in the CSI report. At 212-a, and followingestablishment of the connection, the base station 105-b and UE 115-b maycommunicate via, for example, the shared radio frequency band. Inanother example, the following establishment of the connection, the basestation 105-b and UE 115-b may communicate via, for example, thelicensed radio frequency band.

Wireless communications system 100 may thus advantageously provide for afaster random access procedure thereby enabling a UE to more quicklyreceive network resources for uplink transmission to a base station ascompared to conventional solutions.

FIG. 4 shows a block diagram 400 of a wireless device 405 that supportsCSI reporting for random access procedures in accordance with variousaspects of the present disclosure. Wireless device 405 may be an exampleof aspects of a UE 115 as described with reference to FIGS. 1 and 2.Wireless device 405 may include receiver 410, UE CSI reporting manager415, and transmitter 420. Wireless device 405 may also include aprocessor. Each of these components may be in communication with oneanother (e.g., via one or more buses).

Receiver 410 may receive information such as packets, user data, orcontrol information associated with various information channels (e.g.,control channels, data channels, and information related to CSIreporting for random access procedures, etc.). Information may be passedon to other components of the device. The receiver 410 may be an exampleof aspects of the transceiver 740 as described with reference to FIG. 7.

Receiver 410 may receive, from a base station, a downlink transmissionin a radio frequency spectrum band (e.g., a licensed radio frequencyspectrum band, an unlicensed radio frequency spectrum band). In somecases, receiving the downlink transmission includes detecting a subframetransmitted by the base station.

UE CSI reporting manager 415 may be an example of aspects of the UE CSIreporting manager 715 as described with reference to FIG. 7.

UE CSI reporting manager 415 may identify reference resources in thedownlink transmission for computing a CSI report, generate the CSIreport based on the identified reference resources, and transmit, in theradio frequency spectrum band, the CSI report in a random access requestmessage to the base station.

Transmitter 420 may transmit signals generated by other components ofthe device. In some examples, the transmitter 420 may be collocated witha receiver 410 in a transceiver module. For example, the transmitter 420may be an example of aspects of the transceiver 740 as described withreference to FIG. 7. The transmitter 420 may include a single antenna,or it may include a set of antennas.

FIG. 5 shows a block diagram 500 of a wireless device 505 that supportsCSI reporting for random access procedures in accordance with variousaspects of the present disclosure. Wireless device 505 may be an exampleof aspects of a wireless device 405 or a UE 115 as described withreference to FIGS. 1, 2 and 4. Wireless device 505 may include receiver510, UE CSI reporting manager 515, and transmitter 520. Wireless device505 may also include a processor. Each of these components may be incommunication with one another (e.g., via one or more buses).

Receiver 510 may receive information such as packets, user data, orcontrol information associated with various information channels (e.g.,control channels, data channels, and information related to CSIreporting for random access procedures, etc.). Information may be passedon to other components of the device. The receiver 510 may be an exampleof aspects of the transceiver 740 as described with reference to FIG. 7.

UE CSI reporting manager 515 may be an example of aspects of the UE CSIreporting manager 715 as described with reference to FIG. 7.

UE CSI reporting manager 515 may also include resource identifyingcomponent 525, CSI generating component 530, and CSI reporting component535.

Resource identifying component 525 may identify reference resources inthe downlink transmission for computing a CSI report and receive aconnection pre-establishment message from the base station, whereidentifying the reference resources includes decoding an informationblock included in the connection pre-establishment message, where theinformation block includes an indication that identifies the referenceresources to be used to generate the CSI report. In some cases, thereference resources include a dedicated reference signal used fordownlink synchronization with the base station.

CSI generating component 530 may generate the CSI report based on theidentified reference resources and calculate CSI to be included in theCSI report based on the reference signal. In some cases, the CSI reportincludes a CQI, or a PMI, or a RI, or a combination thereof. In somecases, generating the CSI report further includes processing thereference resources to obtain a reference signal. In some cases, thereference signal is one or more of a dedicated reference signal, acell-specific reference signal, or a CSI reference signal.

CSI reporting component 535 may transmit, in a radio frequency spectrumband, the CSI report in a random access request message to the basestation.

Transmitter 520 may transmit signals generated by other components ofthe device. In some examples, the transmitter 520 may be collocated witha receiver 510 in a transceiver module. For example, the transmitter 520may be an example of aspects of the transceiver 740 as described withreference to FIG. 7. The transmitter 520 may include a single antenna,or it may include a set of antennas.

FIG. 6 shows a block diagram 600 of a UE CSI reporting manager 615 thatsupports CSI reporting for random access procedures in accordance withvarious aspects of the present disclosure. The UE CSI reporting manager615 may be an example of aspects of a UE CSI reporting manager 415, a UECSI reporting manager 515, or a UE CSI reporting manager 715 asdescribed with reference to FIGS. 4, 5, and 7. The UE CSI reportingmanager 615 may include resource identifying component 625, CSIgenerating component 630, and CSI reporting component 635. Each of thesemodules may communicate, directly or indirectly, with one another (e.g.,via one or more buses).

Resource identifying component 625 may identify reference resources inthe downlink transmission for computing a CSI report and receive aconnection pre-establishment message from the base station, whereidentifying the reference resources includes decoding an informationblock included in the connection pre-establishment message, where theinformation block includes an indication that identifies the referenceresources to be used to generate the CSI report. In some cases, thereference resources include a dedicated reference signal used fordownlink synchronization with the base station.

CSI generating component 630 may generate the CSI report based on theidentified reference resources and calculate CSI to be included in theCSI report based on the reference signal. In some cases, the CSI reportincludes a CQI, or a PMI, or a RI, or a combination thereof. In somecases, generating the CSI report further includes processing thereference resources to obtain a reference signal. In some cases, thereference signal is one or more of a dedicated reference signal, acell-specific reference signal, or a CSI reference signal.

CSI reporting component 635 may transmit, in a radio frequency spectrumband, the CSI report in a random access request message to the basestation.

Random access response component 640 may receive, from the base station,a random access response message generated by the base station based onCSI in the CSI report and determine that a random access responsemessage has not yet been received in response to the random accessrequest message.

Random access request component 645 may indicate in the random accessrequest message which one or more of a set of reference resources wasused to generate the CSI report, retransmit the random access requestmessage to the base station in the radio frequency spectrum band, andcalculate an updated CSI report, where the retransmitted random accessrequest message includes the updated CSI report.

FIG. 7 illustrates a block diagram of a system 700 including a wirelessdevice 705 that supports CSI reporting for random access procedures inaccordance with various aspects of the present disclosure. Wirelessdevice 705 may be an example of a wireless device 405, wireless device505, or a UE 115 as described above, e.g., with reference to FIGS. 1, 2,4 and 5.

Wireless device 705 may include components for bi-directional voice anddata communications including components for transmitting and receivingcommunications, including UE CSI reporting manager 715, processor 725,memory 730, software 735, transceiver 740, and antenna 745.

Processor 725 may include an intelligent hardware device, (e.g., acentral processing unit (CPU), a microcontroller, an applicationspecific integrated circuit (ASIC), etc.)

Memory 730 may include random access memory (RAM) and read only memory(ROM). The memory 730 may store computer-readable, computer-executablesoftware 735 including instructions that, when executed, cause theprocessor to perform various functions described herein. In some cases,the memory 730 can contain, among other things, a Basic Input-Outputsystem (BIOS) which may control basic hardware and/or software operationsuch as the interaction with peripheral components or devices.

Software 735 may include code to implement aspects of the presentdisclosure, including code to support CSI reporting for random accessprocedures. Software 735 can be stored in a non-transitorycomputer-readable medium such as system memory or other memory. In somecases, the software 735 may not be directly executable by the processorbut may cause a computer (e.g., when compiled and executed) to performfunctions described herein.

Transceiver 740 may communicate bi-directionally, via one or moreantennas, wired, or wireless links as described above. For example, thetransceiver 740 may represent a wireless transceiver and may communicatebi-directionally with another wireless transceiver. The transceiver 740may also include a modem to modulate the packets and provide themodulated packets to the antennas for transmission, and to demodulatepackets received from the antennas.

In some cases, wireless device 705 may include a single antenna 745.However, in some cases wireless device 705 may have more than oneantenna 745, which may be capable of concurrently transmitting orreceiving multiple wireless transmissions.

FIG. 8 shows a block diagram 800 of a wireless device 805 that supportsCSI reporting for random access procedures in accordance with variousaspects of the present disclosure. Wireless device 805 may be an exampleof aspects of a base station 105 as described with reference to FIGS. 1and 2. Wireless device 805 may include receiver 810, base station CSIreporting manager 815, and transmitter 820. Wireless device 805 may alsoinclude a processor. Each of these components may be in communicationwith one another (e.g., via one or more buses).

Receiver 810 may receive information such as packets, user data, orcontrol information associated with various information channels (e.g.,control channels, data channels, and information related to CSIreporting for random access procedures, etc.). Information may be passedon to other components of the device. The receiver 810 may be an exampleof aspects of the transceiver 1140 as described with reference to FIG.11.

Base station CSI reporting manager 815 may be an example of aspects ofthe base station CSI reporting manager 1115 as described with referenceto FIG. 11.

Base station CSI reporting manager 815 may receive, from a UE, a randomaccess request message in a radio frequency spectrum band, the randomaccess request message including a CSI report, identify CSI associatedwith the radio frequency spectrum band based on the CSI report includedin the random access request message, and transmit, to the UE, a randomaccess response message based on the identified CSI in the radiofrequency spectrum band.

Transmitter 820 may transmit signals generated by other components ofthe device. In some examples, the transmitter 820 may be collocated witha receiver 810 in a transceiver module. For example, the transmitter 820may be an example of aspects of the transceiver 1140 as described withreference to FIG. 11. The transmitter 820 may include a single antenna,or it may include a set of antennas.

FIG. 9 shows a block diagram 900 of a wireless device 905 that supportsCSI reporting for random access procedures in accordance with variousaspects of the present disclosure. Wireless device 905 may be an exampleof aspects of a wireless device 805 or a base station 105 as describedwith reference to FIGS. 1, 2 and 8. Wireless device 905 may includereceiver 910, base station CSI reporting manager 915, and transmitter920. Wireless device 905 may also include a processor. Each of thesecomponents may be in communication with one another (e.g., via one ormore buses).

Receiver 910 may receive information such as packets, user data, orcontrol information associated with various information channels (e.g.,control channels, data channels, and information related to CSIreporting for random access procedures, etc.). Information may be passedon to other components of the device. The receiver 910 may be an exampleof aspects of the transceiver 1140 as described with reference to FIG.11.

Base station CSI reporting manager 915 may be an example of aspects ofthe base station CSI reporting manager 1115 as described with referenceto FIG. 11.

Base station CSI reporting manager 915 may also include request messagecomponent 925, CSI identifying component 930, and response messagecomponent 935.

Request message component 925 may receive, from a UE, a random accessrequest message in a radio frequency spectrum band, the random accessrequest message including a CSI report, and process the random accessrequest message to identify a CSI report indicator indicating that therandom access request message includes the CSI report.

CSI identifying component 930 may identify CSI associated with the radiofrequency spectrum band based on the CSI report included in the randomaccess request message.

Response message component 935 may transmit, to the UE, a random accessresponse message based on the identified CSI in the radio frequencyspectrum band.

Transmitter 920 may transmit signals generated by other components ofthe device. In some examples, the transmitter 920 may be collocated witha receiver 910 in a transceiver module. For example, the transmitter 920may be an example of aspects of the transceiver 1140 as described withreference to FIG. 11. The transmitter 920 may include a single antenna,or it may include a set of antennas.

FIG. 10 shows a block diagram 1000 of a base station CSI reportingmanager 1015 that supports CSI reporting for random access procedures inaccordance with various aspects of the present disclosure. The basestation CSI reporting manager 1015 may be an example of aspects of abase station CSI reporting manager 815, a base station CSI reportingmanager 915, or a base station CSI reporting manager 1115 described withreference to FIGS. 8, 9, and 11. The base station CSI reporting manager1015 may include request message component 1025, CSI identifyingcomponent 1030, and response message component 1035. Each of thesemodules may communicate, directly or indirectly, with one another (e.g.,via one or more buses).

Request message component 1025 may receive, from a UE, a random accessrequest message in a radio frequency spectrum band, the random accessrequest message including a CSI report and process the random accessrequest message to identify a CSI report indicator indicating that therandom access request message includes the CSI report.

CSI identifying component 1030 may identify CSI associated with theradio frequency spectrum band based on the CSI report included in therandom access request message.

Response message component 1035 may transmit, to the UE, a random accessresponse message based on the identified CSI in the radio frequencyspectrum band.

Frequency communication component 1040 may communicate with the UE inthe radio frequency spectrum band based on the identified CSI andtransmit a downlink transmission in the radio frequency spectrum band,the downlink transmission including reference resources to enable the UEto generate the CSI report. In some cases, transmitting the downlinktransmission includes matching a rate of a physical uplink controlchannel to a rate of the reference resources.

Information Block generating component 1045 may generate an informationblock to be included in the downlink transmission. In some cases,transmitting of the downlink transmission includes generating thedownlink transmission to include an information block indicating thatCSI reporting is enabled. In some cases, the information block indicateswideband reporting, sub-band reporting, or UE-selected sub-bandreporting.

FIG. 11 shows a diagram of a system 1100 including a wireless device1105 that supports CSI reporting for random access procedures inaccordance with various aspects of the present disclosure. Wirelessdevice 1105 may be an example of a wireless device 805, wireless device905, or a base station 105 as described above, e.g., with reference toFIGS. 1, 2, 8 and 9.

Wireless device 1105 may include components for bi-directional voice anddata communications including components for transmitting and receivingcommunications, including base station CSI reporting manager 1115,processor 1125, memory 1130, software 1135, transceiver 1140, antenna1145, network communications manager 1150, and base stationcommunications manager 1155.

Processor 1125 may include an intelligent hardware device, (e.g., a CPU,a microcontroller, an application specific integrated circuit (ASIC),etc.)

Memory 1130 may include RAM and ROM. The memory 1130 may storecomputer-readable, computer-executable software 1135 includinginstructions that, when executed, cause the processor to perform variousfunctions described herein. In some cases, the memory 1130 can contain,among other things, a BIOS which may control basic hardware and/orsoftware operation such as the interaction with peripheral components ordevices.

Software 1135 may include code to implement aspects of the presentdisclosure, including code to support CSI reporting for random accessprocedures. Software 1135 can be stored in a non-transitorycomputer-readable medium such as system memory or other memory. In somecases, the software 1135 may not be directly executable by the processorbut may cause a computer (e.g., when compiled and executed) to performfunctions described herein.

Transceiver 1140 may communicate bi-directionally, via one or moreantennas, wired, or wireless links as described above. For example, thetransceiver 1140 may represent a wireless transceiver and maycommunicate bi-directionally with another wireless transceiver. Thetransceiver 1140 may also include a modem to modulate the packets andprovide the modulated packets to the antennas for transmission, and todemodulate packets received from the antennas.

In some cases, the wireless device may include a single antenna 1145.However, in some cases the device may have more than one antenna 1145,which may be capable of concurrently transmitting or receiving multiplewireless transmissions.

Network communications manager 1150 may manage communications with thecore network (e.g., via one or more wired backhaul links). For example,the network communications manager 1150 may manage the transfer of datacommunications for client devices, such as one or more UEs 115.

Base station communications manager 1155 may manage communications withother base station 105, and may include a controller or scheduler forcontrolling communications with UEs 115 in cooperation with other basestations 105. For example, the base station communications manager 1155may coordinate scheduling for transmissions to UEs 115 for variousinterference mitigation techniques such as beamforming or jointtransmission. In some examples, base station communications manager 1155may provide an X2 interface within an LTE/LTE-A wireless communicationnetwork technology to provide communication between base stations 105.

FIG. 12 shows a flowchart illustrating a method 1200 that supports CSIreporting for random access procedures in accordance with variousaspects of the present disclosure. The operations of method 1200 may beimplemented by a UE 115 or its components as described herein. Forexample, the operations of method 1200 may be performed by a UE CSIreporting manager as described with reference to FIGS. 4 through 6. Insome examples, a UE 115 may execute a set of codes to control thefunctional elements of the device to perform the functions describedbelow. Additionally or alternatively, the UE 115 may perform aspects thefunctions described below using special-purpose hardware.

At block 1205, the UE 115 may receive, from a base station, a downlinktransmission in a radio frequency spectrum band. The operations of block1205 may be performed according to the methods as described withreference to FIGS. 2 and 3. In some examples, aspects of the operationsof block 1205 may be performed by a receiver as described with referenceto FIGS. 4 through 6.

At block 1210, the UE 115 may identify reference resources in thedownlink transmission for computing a CSI report. The operations ofblock 1210 may be performed according to the methods as described withreference to FIGS. 2 and 3. In some examples, aspects of the operationsof block 1210 may be performed by a resource identifying component asdescribed with reference to FIGS. 4 through 6.

At block 1215, the UE 115 may generate the CSI report based on theidentified reference resources. The operations of block 1215 may beperformed according to the methods as described with reference to FIGS.2 and 3. In some examples, aspects of the operations of block 1215 maybe performed by a CSI generating component as described with referenceto FIGS. 4 through 6.

At block 1220, the UE 115 may transmit, in the radio frequency spectrumband, the CSI report in a random access request message to the basestation. The operations of block 1220 may be performed according to themethods as described with reference to FIGS. 2 and 3. In some examples,aspects of the operations of block 1220 may be performed by a CSIreporting component as described with reference to FIGS. 4 through 6.

FIG. 13 shows a flowchart illustrating a method 1300 that supports CSIreporting for random access procedures in accordance with variousaspects of the present disclosure. The operations of method 1300 may beimplemented by a UE 115 or its components as described herein. Forexample, the operations of method 1300 may be performed by a UE CSIreporting manager as described with reference to FIGS. 4 through 6. Insome examples, a UE 115 may execute a set of codes to control thefunctional elements of the device to perform the functions describedbelow. Additionally or alternatively, the UE 115 may perform aspects thefunctions described below using special-purpose hardware.

At block 1305, the UE 115 may receive, from a base station, a downlinktransmission in a radio frequency spectrum band. The operations of block1305 may be performed according to the methods as described withreference to FIGS. 2 and 3. In some examples, aspects of the operationsof block 1305 may be performed by a receiver as described with referenceto FIGS. 4 through 6.

At block 1310, the UE 115 may identify reference resources in thedownlink transmission for computing a CSI report. The operations ofblock 1310 may be performed according to the methods as described withreference to FIGS. 2 and 3. In some examples, aspects of the operationsof block 1310 may be performed by a resource identifying component asdescribed with reference to FIGS. 4 through 6.

At block 1315, the UE 115 may generate the CSI report based on theidentified reference resources. The operations of block 1315 may beperformed according to the methods as described with reference to FIGS.2 and 3. In some examples, aspects of the operations of block 1315 maybe performed by a CSI generating component as described with referenceto FIGS. 4 through 6.

At block 1320, the UE 115 may transmit, in the radio frequency spectrumband, the CSI report in a random access request message to the basestation. The operations of block 1320 may be performed according to themethods as described with reference to FIGS. 2 and 3. In some examples,aspects of the operations of block 1320 may be performed by a CSIreporting component as described with reference to FIGS. 4 through 6.

At block 1325, the UE 115 may determine that a random access responsemessage has not yet been received in response to the random accessrequest message. The operations of block 1325 may be performed accordingto the methods as described with reference to FIGS. 2 and 3. In someexamples, aspects of the operations of block 1325 may be performed by arandom access response component as described with reference to FIGS. 4through 6.

At block 1330, the UE 115 may retransmit the random access requestmessage to the base station in the radio frequency spectrum band. Theoperations of block 1330 may be performed according to the methods asdescribed with reference to FIGS. 2 and 3. In some examples, aspects ofthe operations of block 1330 may be performed by a random access requestcomponent as described with reference to FIGS. 4 through 6.

FIG. 14 shows a flowchart illustrating a method 1400 that supports CSIreporting for random access procedures in accordance with variousaspects of the present disclosure. The operations of method 1400 may beimplemented by a UE 115 or its components as described herein. Forexample, the operations of method 1400 may be performed by a UE CSIreporting manager as described with reference to FIGS. 4 through 6. Insome examples, a UE 115 may execute a set of codes to control thefunctional elements of the device to perform the functions describedbelow. Additionally or alternatively, the UE 115 may perform aspects thefunctions described below using special-purpose hardware.

At block 1405, the UE 115 may receive, from a base station, a downlinktransmission in a radio frequency spectrum band. The operations of block1405 may be performed according to the methods as described withreference to FIGS. 2 and 3. In some examples, aspects of the operationsof block 1405 may be performed by a receiver as described with referenceto FIGS. 4 through 6.

At block 1410, the UE 115 may identify reference resources in thedownlink transmission for computing a CSI report. The operations ofblock 1410 may be performed according to the methods as described withreference to FIGS. 2 and 3. In some examples, aspects of the operationsof block 1410 may be performed by a resource identifying component asdescribed with reference to FIGS. 4 through 6.

At block 1415, the UE 115 may generate the CSI report based on theidentified reference resources. The operations of block 1415 may beperformed according to the methods as described with reference to FIGS.2 and 3. In some examples, aspects of the operations of block 1415 maybe performed by a CSI generating component as described with referenceto FIGS. 4 through 6.

At block 1420, the UE 115 may transmit, in the radio frequency spectrumband, the CSI report in a random access request message to the basestation. The operations of block 1420 may be performed according to themethods as described with reference to FIGS. 2 and 3. In some examples,aspects of the operations of block 1420 may be performed by a CSIreporting component as described with reference to FIGS. 4 through 6.

At block 1425, the UE 115 may determine that a random access responsemessage has not yet been received in response to the random accessrequest message. The operations of block 1425 may be performed accordingto the methods as described with reference to FIGS. 2 and 3. In someexamples, aspects of the operations of block 1425 may be performed by arandom access response component as described with reference to FIGS. 4through 6.

At block 1430, the UE 115 may calculate an updated CSI report. Theoperations of block 1430 may be performed according to the methods asdescribed with reference to FIGS. 2 and 3. In some examples, aspects ofthe operations of block 1430 may be performed by a random access requestcomponent as described with reference to FIGS. 4 through 6.

At block 1435, the UE 115 may retransmit the random access requestmessage to the base station in the radio frequency spectrum band. Theretransmitted report may include the previously generated CSI report orthe updated CSI report. The operations of block 1435 may be performedaccording to the methods as described with reference to FIGS. 2 and 3.In some examples, aspects of the operations of block 1435 may beperformed by a random access request component as described withreference to FIGS. 4 through 6.

FIG. 15 shows a flowchart illustrating a method 1500 that supports CSIreporting for random access procedures in accordance with variousaspects of the present disclosure. The operations of method 1500 may beimplemented by a base station 105 or its components as described herein.For example, the operations of method 1500 may be performed by a basestation CSI reporting manager as described with reference to FIGS. 8through 10. In some examples, a base station 105 may execute a set ofcodes to control the functional elements of the device to perform thefunctions described below. Additionally or alternatively, the basestation 105 may perform aspects the functions described below usingspecial-purpose hardware.

At block 1505, the base station 105 may receive, from a UE, a randomaccess request message in a radio frequency spectrum band, the randomaccess request message including a CSI report. The operations of block1505 may be performed according to the methods as described withreference to FIGS. 2 and 3. In some examples, aspects of the operationsof block 1505 may be performed by a request message component asdescribed with reference to FIGS. 8 through 10.

At block 1510, the base station 105 may identify CSI associated with theradio frequency spectrum band based on the CSI report included in therandom access request message. The operations of block 1510 may beperformed according to the methods as described with reference to FIGS.2 and 3. In some examples, aspects of the operations of block 1510 maybe performed by a CSI identifying component as described with referenceto FIGS. 8 through 10.

At block 1515, the base station 105 may transmit, to the UE, a randomaccess response message based on the identified CSI in the radiofrequency spectrum band. The operations of block 1515 may be performedaccording to the methods as described with reference to FIGS. 2 and 3.In some examples, aspects of the operations of block 1515 may beperformed by a response message component as described with reference toFIGS. 8 through 10.

FIG. 16 shows a flowchart illustrating a method 1600 that supports CSIreporting for random access procedures in accordance with variousaspects of the present disclosure. The operations of method 1600 may beimplemented by a base station 105 or its components described herein.For example, the operations of method 1600 may be performed by a basestation CSI reporting manager as described with reference to FIGS. 8through 10. In some examples, a base station 105 may execute a set ofcodes to control the functional elements of the device to perform thefunctions described below. Additionally or alternatively, the basestation 105 may perform aspects the functions described below usingspecial-purpose hardware.

At block 1605, the base station 105 may transmit a downlink transmissionin the radio frequency spectrum band, the downlink transmissionincluding reference resources to enable the UE to generate the CSIreport. The operations of block 1605 may be performed according to themethods as described with reference to FIGS. 2 and 3. In some examples,aspects of the operations of block 1605 may be performed by a frequencycommunication component as described with reference to FIGS. 8 through10.

At block 1610, the base station 105 may receive, from a UE, a randomaccess request message in a radio frequency spectrum band, the randomaccess request message including a CSI report. The operations of block1610 may be performed according to the methods as described withreference to FIGS. 2 and 3. In some examples, aspects of the operationsof block 1610 may be performed by a request message component asdescribed with reference to FIGS. 8 through 10.

At block 1615, the base station 105 may identify CSI associated with theradio frequency spectrum band based on the CSI report included in therandom access request message. The operations of block 1615 may beperformed according to the methods as described with reference to FIGS.2 and 3. In some examples, aspects of the operations of block 1615 maybe performed by a CSI identifying component as described with referenceto FIGS. 8 through 10.

At block 1620, the base station 105 may transmit, to the UE, a randomaccess response message based on the identified CSI in the radiofrequency spectrum band. The operations of block 1620 may be performedaccording to the methods as described with reference to FIGS. 2 and 3.In some examples, aspects of the operations of block 1620 may beperformed by a response message component as described with reference toFIGS. 8 through 10.

In some examples, aspects from two or more of the methods 1200, 1300,1400, 1500, or 1600 as described with reference to FIGS. 12-16 may becombined. It should be noted that the methods 1200, 1300, 1400, 1500,and 1600 are just example implementations, and that the operations ofthe methods 1200, 1300, 1400, 1500, or 1600 may be rearranged orotherwise modified such that other implementations are possible.Furthermore, aspects from two or more of the methods may be combined.

Techniques described herein may be used for various wirelesscommunications systems such as CDMA, TDMA, FDMA, OFDMA, single carrierfrequency division multiple access (SC-FDMA), and other systems. Theterms “system” and “network” are often used interchangeably. A CDMAsystem may implement a radio technology such as CDMA2000, UniversalTerrestrial Radio Access (UTRA), etc. CDMA2000 covers IS-2000, IS-95,and IS-856 standards. IS-2000 Releases may be commonly referred to asCDMA2000 1×, 1×, etc. IS-856 (TIA-856) is commonly referred to asCDMA2000 1×EV-DO, High Rate Packet Data (HRPD), etc. UTRA includesWideband CDMA (WCDMA) and other variants of CDMA. A TDMA system mayimplement a radio technology such as Global System for MobileCommunications (GSM).

An OFDMA system may implement a radio technology such as Ultra MobileBroadband (UMB), Evolved UTRA (E-UTRA), IEEE 802.11 (Wi-Fi), IEEE 802.16(WiMAX), IEEE 802.20, Flash-OFDM, etc. UTRA and E-UTRA are part ofUniversal Mobile Telecommunications system (UMTS). 3GPP LTE and LTE-Aare new releases of UMTS that use E-UTRA. UTRA, E-UTRA, UMTS, LTE,LTE-A, NR, and GSM are described in documents from the organizationnamed “3rd Generation Partnership Project” (3GPP). CDMA2000 and UMB aredescribed in documents from an organization named “3rd GenerationPartnership Project 2” (3GPP2). The techniques described herein may beused for the systems and radio technologies mentioned above as well asother systems and radio technologies. While aspects of an LTE system oran NR system may be described for purposes of example, and LTE or NRterminology may be used in much of the description, the techniquesdescribed herein are applicable beyond LTE or NR applications.

In LTE/LTE-A networks, including such networks described herein, theterm evolved node B (eNB) may be generally used to describe the basestations. The wireless communications system or systems described hereinmay include a heterogeneous LTE/LTE-A or NR network in which differenttypes of evolved node B (eNBs) provide coverage for various geographicalregions. For example, each eNB or base station may provide communicationcoverage for a macro cell, a small cell, or other types of cell. Theterm “cell” is a 3GPP term that can be used to describe a base station,a carrier or component carrier associated with a base station, or acoverage area (e.g., sector, etc.) of a carrier or base station,depending on context.

Base stations may include or may be referred to by those skilled in theart as a base transceiver station, a radio base station, an accesspoint, a radio transceiver, a NodeB, eNodeB (eNB), Home NodeB, a HomeeNodeB, or some other suitable terminology. The geographic coverage areafor a base station may be divided into sectors making up only a portionof the coverage area. The wireless communications system or systemsdescribed herein may include base stations of different types (e.g.,macro or small cell base stations). The UEs described herein may be ableto communicate with various types of base stations and network equipmentincluding macro eNBs, small cell eNBs, relay base stations, or the like.There may be overlapping geographic coverage areas for differenttechnologies.

A macro cell generally covers a relatively large geographic area (e.g.,several kilometers in radius) and may allow unrestricted access by UEswith service subscriptions with the network provider. A small cell is alower-powered base station, as compared with a macro cell, that mayoperate in the same or different (e.g., licensed, unlicensed, etc.)frequency bands as macro cells. Small cells may include pico cells,femto cells, and micro cells according to various examples. A pico cell,for example, may cover a small geographic area and may allowunrestricted access by UEs with service subscriptions with the networkprovider. A femto cell may also cover a small geographic area (e.g., ahome) and may provide restricted access by UEs having an associationwith the femto cell (e.g., UEs in a closed subscriber group (CSG), UEsfor users in the home, or the like). An eNB for a macro cell may bereferred to as a macro eNB. An eNB for a small cell may be referred toas a small cell eNB, a pico eNB, a femto eNB, or a home eNB. An eNB maysupport one or multiple (e.g., two, three, four, or the like) cells(e.g., component carriers). A UE may be able to communicate with varioustypes of base stations and network equipment including macro eNBs, smallcell eNBs, relay base stations, or the like.

The wireless communications system or systems described herein maysupport synchronous or asynchronous operation. For synchronousoperation, the base stations may have similar frame timing, andtransmissions from different base stations may be approximately alignedin time. For asynchronous operation, the base stations may havedifferent frame timing, and transmissions from different base stationsmay not be aligned in time. The techniques described herein may be usedfor either synchronous or asynchronous operations.

The downlink transmissions described herein may also be called forwardlink transmissions while the uplink transmissions may also be calledreverse link transmissions. Each communication link describedherein—including, for example, wireless communications system 100 ofFIG. 1—may include one or more carriers, where each carrier may be asignal made up of multiple sub-carriers (e.g., waveform signals ofdifferent frequencies).

The description set forth herein, in connection with the appendeddrawings, describes example configurations and does not represent allthe examples that may be implemented or that are within the scope of theclaims. The term “exemplary” used herein means “serving as an example,instance, or illustration,” and not “preferred” or “advantageous overother examples.” The detailed description includes specific details forthe purpose of providing an understanding of the described techniques.These techniques, however, may be practiced without these specificdetails. In some instances, well-known structures and devices are shownin block diagram form in order to avoid obscuring the concepts of thedescribed examples.

In the appended figures, similar components or features may have thesame reference label. Further, various components of the same type maybe distinguished by following the reference label by a dash and a secondlabel that distinguishes among the similar components. If just the firstreference label is used in the specification, the description isapplicable to any one of the similar components having the same firstreference label irrespective of the second reference label.

Information and signals described herein may be represented using any ofa variety of different technologies and techniques. For example, data,instructions, commands, information, signals, bits, symbols, and chipsthat may be referenced throughout the above description may berepresented by voltages, currents, electromagnetic waves, magneticfields or particles, optical fields or particles, or any combinationthereof.

The various illustrative blocks and modules described in connection withthe disclosure herein may be implemented or performed with ageneral-purpose processor, a digital signal processor (DSP), an ASIC, afield-programmable gate array (FPGA) or other programmable logic device,discrete gate or transistor logic, discrete hardware components, or anycombination thereof designed to perform the functions described herein.A general-purpose processor may be a microprocessor, but in thealternative, the processor may be any conventional processor,controller, microcontroller, or state machine. A processor may also beimplemented as a combination of computing devices (e.g., a combinationof a DSP and a microprocessor, multiple microprocessors, one or moremicroprocessors in conjunction with a DSP core, or any other suchconfiguration).

The functions described herein may be implemented in hardware, softwareexecuted by a processor, firmware, or any combination thereof. Ifimplemented in software executed by a processor, the functions may bestored on or transmitted over as one or more instructions or code on acomputer-readable medium. Other examples and implementations are withinthe scope and spirit of the disclosure and appended claims. For example,due to the nature of software, functions described above can beimplemented using software executed by a processor, hardware, firmware,hardwiring, or combinations of any of these. Features implementingfunctions may be physically located at various positions, includingbeing distributed such that portions of functions are implemented atdifferent physical locations. As used herein, including in the claims,the term “and/or,” when used in a list of two or more items, means thatany one of the listed items can be employed by itself, or anycombination of two or more of the listed items can be employed. Forexample, if a composition is described as containing components A, B,and/or C, the composition can contain A alone; B alone; C alone; A and Bin combination; A and C in combination; B and C in combination; or A, B,and C in combination. Also, as used herein, including in the claims,“or” as used in a list of items (for example, a list of items prefacedby a phrase such as “at least one of” or “one or more of”) indicates aninclusive list such that, for example, a phrase referring to “at leastone of” a list of items refers to any combination of those items,including single members. As an example, “at least one of: A, B, or C”is intended to cover A, B, C, A-B, A-C, B-C, and A-B-C., as well as anycombination with multiples of the same element (e.g., A-A A-A-A, A-A-B,A-A-C, A-B-B, A-C-C, B-B, B-B-B, B-B-C, C-C, and C-C-C or any otherordering of A, B, and C).

As used herein, the phrase “based on” shall not be construed as areference to a closed set of conditions. For example, an exemplaryfeature that is described as “based on condition A” may be based on botha condition A and a condition B without departing from the scope of thepresent disclosure. In other words, as used herein, the phrase “basedon” shall be construed in the same manner as the phrase “based at leastin part on.”

Computer-readable media includes both non-transitory computer storagemedia and communication media including any medium that facilitatestransfer of a computer program from one place to another. Anon-transitory storage medium may be any available medium that can beaccessed by a general purpose or special purpose computer. By way ofexample, and not limitation, non-transitory computer-readable media cancomprise RAM, ROM, electrically erasable programmable read only memory(EEPROM), compact disk (CD) ROM or other optical disk storage, magneticdisk storage or other magnetic storage devices, or any othernon-transitory medium that can be used to carry or store desired programcode means in the form of instructions or data structures and that canbe accessed by a general-purpose or special-purpose computer, or ageneral-purpose or special-purpose processor. Also, any connection isproperly termed a computer-readable medium. For example, if the softwareis transmitted from a website, server, or other remote source using acoaxial cable, fiber optic cable, twisted pair, digital subscriber line(DSL), or wireless technologies such as infrared, radio, and microwave,then the coaxial cable, fiber optic cable, twisted pair, DSL, orwireless technologies such as infrared, radio, and microwave areincluded in the definition of medium. Disk and disc, as used herein,include CD, laser disc, optical disc, digital versatile disc (DVD),floppy disk and Blu-ray disc where disks usually reproduce datamagnetically, while discs reproduce data optically with lasers.Combinations of the above are also included within the scope ofcomputer-readable media.

The description herein is provided to enable a person skilled in the artto make or use the disclosure. Various modifications to the disclosurewill be readily apparent to those skilled in the art, and the genericprinciples defined herein may be applied to other variations withoutdeparting from the scope of the disclosure. Thus, the disclosure is notlimited to the examples and designs described herein, but is to beaccorded the broadest scope consistent with the principles and novelfeatures disclosed herein.

What is claimed is:
 1. A method for wireless communication, comprising:receiving, from a base station, a downlink transmission in a radiofrequency spectrum band; identifying reference resources in the downlinktransmission for computing a channel state information (C SI) report;generating the CSI report based at least in part on the identifiedreference resources; and transmitting, in the radio frequency spectrumband, the CSI report in a random access request message to the basestation.
 2. The method of claim 1, further comprising: receiving, fromthe base station, a random access response message generated by the basestation based at least in part on CSI in the CSI report.
 3. The methodof claim 1, further comprising: receiving a connection pre-establishmentmessage from the base station, wherein identifying the referenceresources comprises decoding an information block included in theconnection pre-establishment message, wherein the information blockcomprises an indication that identifies the reference resources to beused to generate the CSI report.
 4. The method of claim 1, whereinreceiving the downlink transmission comprises: detecting a subframetransmitted by the base station.
 5. The method of claim 1, wherein theCSI report comprises a channel quality indicator, or a precoding matrixindicator, or a rank indicator, or a combination thereof.
 6. The methodof claim 1, wherein the reference resources comprise a dedicatedreference signal used for downlink synchronization with the basestation.
 7. The method of claim 1, wherein generating the CSI reportfurther comprises: processing the reference resources to obtain areference signal; and calculating CSI to be included in the CSI reportbased at least in part on the reference signal.
 8. The method of claim7, wherein the reference signal is one or more of a dedicated referencesignal, a cell-specific reference signal, or a CSI reference signal. 9.The method of claim 1, further comprising: indicating in the randomaccess request message which one or more of a plurality of referenceresources was used to generate the CSI report.
 10. The method of claim1, further comprising: determining that a random access response messagehas not yet been received in response to the random access requestmessage; and retransmitting the random access request message to thebase station in the radio frequency spectrum band.
 11. The method ofclaim 10, further comprising: calculating an updated CSI report, whereinthe retransmitted random access request message comprises the updatedCSI report.
 12. The method of claim 1, wherein the radio frequencyspectrum band comprises a shared radio frequency spectrum band.
 13. Amethod for wireless communication, comprising: receiving, from a userequipment (UE), a random access request message in a radio frequencyspectrum band, the random access request message including a CSI report;identifying channel state information (CSI) associated with the radiofrequency spectrum band based at least in part on the CSI reportincluded in the random access request message; and transmitting, to theUE, a random access response message based at least in part on theidentified CSI in the radio frequency spectrum band.
 14. The method ofclaim 13, further comprising: communicating with the UE in the radiofrequency spectrum band based at least in part on the identified CSI.15. The method of claim 13, further comprising: transmitting a downlinktransmission in the radio frequency spectrum band, the downlinktransmission comprising reference resources to enable the UE to generatethe CSI report.
 16. The method of claim 15, wherein transmitting thedownlink transmission comprises: matching a rate of a physical uplinkcontrol channel to a rate of the reference resources.
 17. The method ofclaim 15, wherein transmitting of the downlink transmission comprises:generating the downlink transmission to include an information blockindicating that CSI reporting is enabled.
 18. The method of claim 17,wherein the information block indicates wideband reporting, sub-bandreporting, or UE-selected sub-band reporting.
 19. The method of claim13, further comprising: processing the random access request message toidentify a CSI report indicator indicating that the random accessrequest message includes the CSI report.
 20. The method of claim 13,wherein the radio frequency spectrum band comprises a shared radiofrequency spectrum band.
 21. An apparatus for wireless communication,comprising: a processor; memory in electronic communication with theprocessor; and instructions stored in the memory and executable by theprocessor to cause the apparatus to: receive, from a base station, adownlink transmission in a radio frequency spectrum band; identifyreference resources in the downlink transmission for computing a channelstate information (C SI) report; generate the CSI report based at leastin part on the identified reference resources; and transmit, in theradio frequency spectrum band, the CSI report in a random access requestmessage to the base station.
 22. The apparatus of claim 21, wherein theinstructions are further executable by the processor to cause theapparatus to: receive, from the base station, a random access responsemessage generated by the base station based at least in part on CSI inthe CSI report.
 23. The apparatus of claim 21, wherein generating theCSI report comprises further instructions executable by the processor tocause the apparatus to: process the reference resources to obtain areference signal; and calculate CSI to be included in the CSI reportbased at least in part on the reference signal.
 24. The apparatus ofclaim 21, wherein the instructions are further executable by theprocessor to cause the apparatus to: indicate in the random accessrequest message which one or more of a plurality of reference resourceswas used to generate the CSI report.
 25. The apparatus of claim 21,wherein the instructions are further executable by the processor tocause the apparatus to: determine that a random access response messagehas not yet been received in response to the random access requestmessage; and retransmit the random access request message to the basestation in the radio frequency spectrum band.
 26. The apparatus of claim25, wherein the instructions are further executable by the processor tocause the apparatus to: calculate an updated CSI report, wherein theretransmitted random access request message comprises the updated CSIreport.
 27. An apparatus for wireless communication, comprising: aprocessor; memory in electronic communication with the processor; andinstructions stored in the memory and executed by the processor to causethe apparatus to: receive, from a user equipment (UE), a random accessrequest message in a radio frequency spectrum band, the random accessrequest message including a CSI report; identify channel stateinformation (CSI) associated with the radio frequency spectrum bandbased at least in part on the CSI report included in the random accessrequest message; and transmit, to the UE, a random access responsemessage based at least in part on the identified CSI in the radiofrequency spectrum band.
 28. The apparatus of claim 27, wherein theinstructions are further executable by the processor to cause theapparatus to: transmit a downlink transmission in the radio frequencyspectrum band, the downlink transmission comprising reference resourcesto enable the UE to generate the CSI report.
 29. The apparatus of claim28, wherein transmitting the downlink transmission comprises furtherinstructions executable by the processor to cause the apparatus to:match a rate of a physical uplink control channel to a rate of thereference resources; and generate the downlink transmission to includean information block indicating that CSI reporting is enabled.
 30. Theapparatus of claim 27, wherein the instructions are further executableby the processor to cause the apparatus to: process the random accessrequest message to identify a CSI report indicator indicating that therandom access request message includes the CSI report.